# () 不可改变
print((1,'-1',True,[5])[3])
print(type((1,'-1',True,[5])))
print(type((1,23,3)))
print(len((1,23,3,'1')*4))
print(type((1)))    #有歧义(1) == 1
print(type((1,)))   #消除歧义
print(type(()))